"""
Support for Homekit buttons.

These are mostly used where a HomeKit accessory exposes additional non-standard
characteristics that don't map to a Home Assistant feature.
"""
from __future__ import annotations

from dataclasses import dataclass

from aiohomekit.model.characteristics import Characteristic, CharacteristicsTypes

from homeassistant.components.button import (
    ButtonDeviceClass,
    ButtonEntity,
    ButtonEntityDescription,
)
from homeassistant.config_entries import ConfigEntry
from homeassistant.core import HomeAssistant, callback
from homeassistant.helpers.entity import EntityCategory
from homeassistant.helpers.entity_platform import AddEntitiesCallback
from homeassistant.helpers.typing import ConfigType

from . import KNOWN_DEVICES, CharacteristicEntity
from .connection import HKDevice


@dataclass
class HomeKitButtonEntityDescription(ButtonEntityDescription):
    """Describes Homekit button."""

    write_value: int | str | None = None


BUTTON_ENTITIES: dict[str, HomeKitButtonEntityDescription] = {
    CharacteristicsTypes.VENDOR_HAA_SETUP: HomeKitButtonEntityDescription(
        key=CharacteristicsTypes.VENDOR_HAA_SETUP,
        name="Setup",
        icon="mdi:cog",
        entity_category=EntityCategory.CONFIG,
        write_value="#HAA@trcmd",
    ),
    CharacteristicsTypes.VENDOR_HAA_UPDATE: HomeKitButtonEntityDescription(
        key=CharacteristicsTypes.VENDOR_HAA_UPDATE,
        name="Update",
        device_class=ButtonDeviceClass.UPDATE,
        entity_category=EntityCategory.CONFIG,
        write_value="#HAA@trcmd",
    ),
    CharacteristicsTypes.IDENTIFY: HomeKitButtonEntityDescription(
        key=CharacteristicsTypes.IDENTIFY,
        name="Identify",
        entity_category=EntityCategory.DIAGNOSTIC,
        write_value=True,
    ),
}


async def async_setup_entry(
    hass: HomeAssistant,
    config_entry: ConfigEntry,
    async_add_entities: AddEntitiesCallback,
) -> None:
    """Set up Homekit buttons."""
    hkid = config_entry.data["AccessoryPairingID"]
    conn = hass.data[KNOWN_DEVICES][hkid]

    @callback
    def async_add_characteristic(char: Characteristic) -> bool:
        entities = []
        info = {"aid": char.service.accessory.aid, "iid": char.service.iid}

        if description := BUTTON_ENTITIES.get(char.type):
            entities.append(HomeKitButton(conn, info, char, description))
        elif entity_type := BUTTON_ENTITY_CLASSES.get(char.type):
            entities.append(entity_type(conn, info, char))
        else:
            return False

        async_add_entities(entities, True)
        return True

    conn.add_char_factory(async_add_characteristic)


class HomeKitButton(CharacteristicEntity, ButtonEntity):
    """Representation of a Button control on a homekit accessory."""

    entity_description: HomeKitButtonEntityDescription

    def __init__(
        self,
        conn: HKDevice,
        info: ConfigType,
        char: Characteristic,
        description: HomeKitButtonEntityDescription,
    ) -> None:
        """Initialise a HomeKit button control."""
        self.entity_description = description
        super().__init__(conn, info, char)

    def get_characteristic_types(self) -> list[str]:
        """Define the homekit characteristics the entity is tracking."""
        return [self._char.type]

    @property
    def name(self) -> str:
        """Return the name of the device if any."""
        if name := super().name:
            return f"{name} {self.entity_description.name}"
        return f"{self.entity_description.name}"

    async def async_press(self) -> None:
        """Press the button."""
        key = self.entity_description.key
        val = self.entity_description.write_value
        await self.async_put_characteristics({key: val})


class HomeKitEcobeeClearHoldButton(CharacteristicEntity, ButtonEntity):
    """Representation of a Button control for Ecobee clear hold request."""

    def get_characteristic_types(self) -> list[str]:
        """Define the homekit characteristics the entity is tracking."""
        return []

    @property
    def name(self) -> str:
        """Return the name of the device if any."""
        prefix = ""
        if name := super().name:
            prefix = name
        return f"{prefix} Clear Hold"

    async def async_press(self) -> None:
        """Press the button."""
        key = self._char.type

        # If we just send true, the request doesn't always get executed by ecobee.
        # Sending false value then true value will ensure that the hold gets cleared
        # and schedule resumed.
        # Ecobee seems to cache the state and not update it correctly, which
        # causes the request to be ignored if it thinks it has no effect.

        for val in (False, True):
            await self.async_put_characteristics({key: val})


BUTTON_ENTITY_CLASSES: dict[str, type] = {
    CharacteristicsTypes.VENDOR_ECOBEE_CLEAR_HOLD: HomeKitEcobeeClearHoldButton,
}